Statistical Thermodynamics of Dislocations in Solids

TL;DR

This paper reviews the thermodynamic dislocation theory, emphasizing the effective temperature, and argues for its importance in understanding various deformation phenomena and fracture in crystalline solids.

Contribution

It demonstrates that statistical thermodynamics is applicable to dislocations, challenging longstanding beliefs, and highlights its potential to explain complex material behaviors from first principles.

Findings

Thermodynamic dislocation theory explains strain hardening and shear banding.

Effective temperature is crucial in dislocation thermodynamics.

The theory offers insights into brittle and ductile fracture mechanisms.

Abstract

This review is a simplified summary of the thermodynamic dislocation theory, with special emphasis on the role of an effective temperature. Materials scientists, for decades, have asserted that statistical thermodynamics is not applicable to dislocations. By use of simple, first-principles analyses and comparisons with experimental data, I argue that these scientists have been wrong, and that this venerable field urgently needs to be revitalized because of its wide-ranging fundamental and technological importance. In addition to describing recent progress in understanding strain hardening, yielding, shear banding, and the like, I argue that the thermodynamic dislocation theory can lead to a much needed, first-principles understanding of brittle and ductile fracture in crystalline solids.